Process of making alkyl sulphates



n formation of other Patented Aug. 30,1927;

UNITED STATES mm: n. McKEE, or-NEw'YoRx, N. Y.

PROCESS OF MAKING ALKYL SULPHA TES.

NoDrawing'. Application filed May 21, 1323, Serial No. 640,551.

This invention relates to processes of making alkyl sulphates, and moreparticularly to the manufacture of an alykl sulphate, such as di-ethylsulphate, by the re- 5 action of sulphuryl chlorid on the corre spondingalcohol, such as ethyl alcohol.

.In the manufacture of alykl sulphates by known methods, an alcoholis-usua ly treated with sulphuric acid and the resulting,

I material distilled under-reduced, pressure to obtain thedesiredsulphate. This method is open to the disadvantages that it results inthe formation 'of hydrocarbon by -prodnets and in general gives a lowyield.

11' It has also. been proposed to make dimethyl sulphate by runningsulphur dioxid and chlorine simultaneously or successively into methylalcohol. This process is said -to produce a yield of approximately 50per cent di-methyl sulphate, but it is open to the disadvantage thatabout the same amount of methyl chlorid is formed. Each of theseprocesses are unsatisfactory in that'they do not work smoothly, producelow'yields, and 2 large amounts of by-products. The manufacture ofdi-ethyl sulphate. and ethyl, ,-chlorid by mixing sulphuryl chlorid andethyl alcohol has been proposed, but experiments along these lines haveresulted in the sulphonic acid p p I An-object of theinvention istherevision.

of a more simple method of obtaining d1- ethylsulphate, andsimila'ralkylsulphates, 86 and good yields from sulphuryl.

chlorid and etl lgl alcohol or other alcohols. dition of sulphurylchlorid to ;the alcohol.

If the-addition is in the reverse direction,

- 40. ethyl hydrogen sulphate is formed .in large. quantities instead ofdi-ethyl sulphate. The best yields are obtained by adding one mOleQ-jular equivalent of sulphuryl chlorid to one molecular equivalent ofalcohol, r-suchas ethyl alcohol, at a'temperature. of approxlmately30 0.'Some ethyl chlorid is formed,

but itis present in very small quantity, whereas under known a majorproduct. In practicing the. oc'ess, the sulphu'fiyl chlorid is added toe hylalcohol when ethyl sulphate is to be formed or to othercorresponding alcohols when other alkyl sulphates are tobe formed.Absolute ethyl 65 alcohol is referred over 95 per cent alcohol,

v althought e latter may be used. As stated,

approximately 30 the walls of the distillation; products, such as chlor-Iholecule of. ethyl alcoh theoretical amount of sulphuryl alcohol forhe process-consists essentially in the ad-:

fsimilar ethyl sulphates.

processes, it hasbeen Renewed July 13,1927.

it is essential that the sulphuryl chlorid be added to the alcohol topreventthe formation of ethyl hydrogen sulphate. The sulphuryl chloridis preferably added in the proportion of one molecular equivalent ofsulphuryl chlorid to one molecular equivalent of ethyl alcohol at atemperature of C. The material is stirred vigorously during the additionof the sulphuryl chlorid as considerable heat is evolved and this must.be removed through vessel during the process. To separate the sulphatefrom the other materials produced, the temperature is raised until theexcess sulphuryl chlorid has been removed by distillation. A temperatureof from 100 to 120 C. is employed for the removal of the excess reagent.is then cooledto about C. and run into cooled -water.

to Under some circumstances, it may be further purifiedby distillationin a partial vacuum ut this is l usually unnecessary.- A considerablequantity of unused alcohol maybe recovered from the wash water by simpleOne molecule: ofdsulphur double the the equation. .The react accordingto the equation ,so o1,+ o;ri;oii= C,H,)',SO,+2HC1. While the processabove described is exceed n'gly simple, it is by far-the cheapest methodof making di-ethyl sulphate and ta'mable in commercialquantities.- Avery good-yield of the desiredsulphate is obtained and the recovery ofthe sulphate and the simple.

l chlorid to one A i'on'itakes place- 3 The mixture The di-ethylsulphate settles out in the form of a heavy liquid which 'may be washedwith fresh water and dried form a. commercially 'pure :product.

.7 The process yields itself readily to manufacture on a lar e scale andthe reacting substancesare rea ily obexcess sulphuryl chlorid 1Sexceedingly As stated, the use of one molecular equiva- I lent ofalcohol to one molecular equivalent of sulphuryl chlorid in which the5111- phuryl chlorid temperature of substantially portant to obtain aphate.

Other similar alkyl sulphates, 'suchas di' methyl sulphate, dibutylsulphate, and di- -30 C. is im good yield of ethyl sulis added to thealcohol at a amyl sulphate may be formed by employin the correspondingalcohols in place of ethyl alcohol.

While I have described'in detail the preferred practice of my process,it is to be understood that the details of procedure and proportion ofingredients may be Widely varied, and that known chemical equivalentsmay be employed in place of the materials mentioned, without departingfrom the spirit of the invention or the scope of the subjoined claims.

Having claim:

1. The process of making alkyl sulphate thus described my invention, I

which comprises adding sulphuryl chlorid to an. alcohol at a temperatureof substantially 30 C.

2. The process of making di-ethyl sulphate which comprises addingsulphuryl chlorid to ethyl alcohol at a temperature of substantially 30C. 3. The process of making di-ethyl sulphate which comprises addingsulphurylwhich comprises, adding sulphuryl chlorid to an alcohol,stirring the material to remove the heat evolved, and maintaining atemperature of substantially 39 C.

In testimony whereof. I aflix my signature.

RALPH H. MoKEE.

